I have a conservatory with a concrete floor which stupidley we had a
hardwood blocks laid on top of. These keep shrinking and expanding
with the sun and look a mess, and I would therefore like to replace
them with floor tiles. If I take up the blocks how will I get the tar
that holds them down up, and how clean do I need to have the concrete
of the tar stuff that they are bonded with. I did not lay the blocks
so am not exactly sure what they are put down with but remember a
green tub with something in it that looked like brown tar.
Any advice would be appreciated.

Steve